Ultrasonic diagnosis allows to display in real time how the heart beats or the fetus moves, by simply bringing an ultrasonic probe into contact with the body surface. This technique is highly safe, and hence allows repetitive examination. Furthermore, this system is smaller in size than other diagnostic apparatuses such as X-ray, CT, and MRI apparatuses. This technique can therefore be said to be a simple diagnostic technique which facilitates examination to be performed by moving the apparatus to the bed side. Ultrasonic diagnostic apparatuses used in this ultrasonic diagnosis vary in type depending on the functions which they have. Some compact apparatuses which have already been developed are small enough to be carried with one hand, and ultrasonic diagnosis is free from the influence of radiation exposure unlike diagnosis using X-rays. Therefore, such ultrasonic diagnostic apparatuses can be used in obstetric treatment, treatment at home, and the like.
A Doppler spectrum method is available as a method of obtaining blood flow information in a blood vessel or the heart in an object quantitatively with high accuracy in such ultrasonic diagnosis. The Doppler spectrum method ultrasonically scans a desired region in a blood vessel or in the heart, and performs computation such as FFT for a reception signal corresponding to a desired range gate, thereby obtaining a Doppler spectrum (Doppler frequency). This Doppler spectrum is a graph (waveform) with the abscissa representing the time, and the ordinate representing the frequency, and expresses the intensity of each frequency component as the luminance of an image. In addition, in order to evaluate the function of a cardiac such as the heart, various kinds of measurement values such as left ventricular inflow and outflow are calculated from the obtained Doppler spectrum.
In general, however, cardiac Doppler measurement (in particular, in the cardiac cavity) may not be able to acquire a proper Doppler spectrum due to the mixing of unnecessary signals from a valve or a tendinous chord owing to arrhythmia or the like. In such a case, the operator manually corrects an imperfect Doppler spectrum, manually calculates measurement values from a selected Doppler spectrum, or redoes measurement. In addition, only limited parameters have been automatically calculated in Doppler measurement, and hence the operator has manually calculated several parameters associated with a blood flow. This complicates operation in cardiac Doppler measurement, resulting in a factor that reduces diagnostic efficiency.
In consideration of the above situation, it is provided that an ultrasonic diagnostic apparatus, Doppler measurement apparatus, and Doppler measurement method which can automate or semi-automate various kinds of manual procedures occupying most of the operation in cardiac Doppler measurement, and attribute to a reduction in operation load in cardiac Doppler measurement, an improvement in operation efficiency, and a reduction in variations in measurement result.